1. Field of Endeavor
The present invention relates to filters and other equipment and more particularly to securing filter elements.
2. State of Technology
U.S. Pat. No. 8,197,685 for a filter element, securing ring and method for filtering provides the state of technology information reproduced below.
One basic idea of the invention is to achieve a reliable and leak-proof connection of two connecting means by radially pressing one connecting means against the other. The radial pressing enhances the tightness of the connection and seals the two connecting means.
An important aspect of the invention is to provide a separate element—namely the securing ring—in addition to the first and second connecting means in order to tightly couple the connecting means. The provision of a separate element allows for a quick and easy assembly of the filter element. In a first step, the tubular portion of the first connecting means is introduced into the tubular portion of the second connecting means. This step can be easily accomplished without an excessively tight fit, i.e. high friction, between the two connecting means. In a second step, the securing ring is inserted into the tubular portion of the first connecting means, pressing the tubular portion of the first connecting means against the tubular portion of the second connecting means. With the securing ring, the friction between the two elements is increased, achieving a friction fit and/or a sealed connection between the first and second connecting means.
In order for the pressure exerted by the securing ring to be transferred via the first connecting means to the second connecting means, it is preferred by the invention that at least one of the first and second connecting means comprises a resilient material, particularly a rubber material. The resilient material can also be a thermoplastic elastomer. In this regard, it is particularly preferred that the first connecting means is made up of a resilient material. In other words, the first connecting means should be adapted to allow for an at least slight increase of the diameter of its for example tubular portion.
Another preferred embodiment of the invention is characterized in that the tubular portions of the first and second connecting means comprise corresponding engagement means provided on an outer surface of the tubular portion of the first connecting means and an inner surface of the tubular portion of the second connecting means, respectively. These additional engagement means enhance the tightness of the connection by providing a form-locking or snap connection in addition to the frictional connection. Moreover, the engagement means can assist an operator in identifying a desired relative position of the two connecting means by providing a tactile feedback once the desired position is reached. The engagement means preferably include at least one protrusion and one recess, in particular a circular protrusion and a corresponding circular recess. The protrusion and the recess could also comprise another cross-sectional shape like a square or rectangle etc.
According to another preferred embodiment, the first connecting means comprises a ring-shaped receiving portion provided at an inner surface of its tubular portion for receiving the securing ring. The receiving portion is preferably constructed as a circular groove having a width substantially equal to a width of the securing ring. The receiving portion allows for a defined placement of the securing ring in the tubular portion of the first connecting means. Moreover, the receiving portion securely retains the securing ring in place.
U.S. Pat. No. 7,959,803 for devices, systems and methods for securing and sealing filter media elements in separation systems provides the state of technology information reproduced below.
The present invention relates to devices, systems and methods for securing and sealing filter media in separation systems, and, particularly to devices, systems and methods for securing filter media elements in separations systems for the separation of particulates from fluids.
In a number of situations arising in many settings, it is desirable to separate mixtures of materials. For example, it is often desirable to remove particles from a liquid “contaminated” with such particles. For example, in the machining industry coolant liquid becomes contaminated with metal particles. Such particles can be separated using filter media elements such as filter bags, baskets and cartridges which separate by size exclusion.
Some separations systems have used O-ring type seals in an attempt to limit leakage of fluid to be filtered around a filter element with limited success. See, for example, U.S. Pat. No. 5,462,678, in which an O-ring is used to form a seal between an outer sieve basket and an inner wall of a separation system housing. Indeed, although there has long been a need to decrease the amount of such leakage, currently available separation systems have been unable to satisfy that need.
It is desirable to develop improved devices, systems and methods that reduce or eliminate the above-identified and other problems associated with currently available separation systems.
U.S. Pat. No. 4,632,681 for a locking apparatus for filter elements provides the state of technology information reproduced below.
This invention relates to locking apparatus for filter elements, and more particularly, to apparatus for releasably locking one or more filter elements into sealing engagement with a tube sheet or the like in a dust collector filter assembly.
By way of background, dust collectors of the type here contemplated generally include a large housing divided by a tube sheet into a lower dirty air chamber and an upper clean air chamber. Several rows of cylindrical filter elements are releasably mounted in the lower chamber in sealing engagement with the lower surface of the tube sheet so that their open upper ends register respectively with corresponding openings in the tube sheet and the interiors of the elements communicate with the upper clean air chamber. More specifically, each filter element is provided with a mounting plate in the form of a flange surrounding its upper end and it is these flanges that are mounted in sealing engagement with the tube sheet, a suitable gasket being secured to each mounting plate about the open upper end of the filter elements for effecting an air tight seal with the tube sheet.
Air laden with dust particles, for example, is fed into the lower chamber and passes through the filter elements, which remove the particles from the air, and thence into the upper chamber from which the filtered, clean air may be taken.
It is known to clean the filter elements periodically by applying downwardly directed pulses of air to the interior of each element in opposition to the direction of flow of the air being treated, thus releasing accumulated dust particles from the filter elements. The released particles accumulate in the lower chamber from which they can be removed. While this procedure of course extends the life of the filter elements, they must nevertheless be replaced from time to time.
Heretofore the filter element replacement procedure has been cumbersome, time-consuming and unpleasant and efforts have been made to provide apparatus of the class described which reduce the difficulties and time necessary to replace the filter elements. Thus, it is known from U.S. Pat. No. 4,322,231 to provide a locking arrangement by which filter elements are releasably held against the underside of the apertured tube sheet which carries pairs of locking bars, each pair supporting a row of filter elements. Each bar is semicircular in cross-section so as to define a flat supporting surface and a curved camming surface, the bars being maintained in position by a number of support brackets fixed to transverse beams depending from the tube sheet. Each bracket is formed with at least a trough within which the bars are seated and a handle is affixed to each of the bars and extends perpendicularly from the longitudinal axis of its respective bar.
When the handles are in vertical position, the underside of mounting plates associated with the filter elements, are allowed to rest on the flat surfaces of the associated locking bars so that the filter elements can slide along the bars and out of the filter housing when replacement is required.
To secure the filter elements in active position, the handles are rotated to a horizontal position causing the curved camming surfaces to bear against the underside of the mounting plates forcing the filter elements into engagement with the undersurface of the tube sheet. A gasket is secured to each mounting plate about the open upper end of the filter elements to effect a seal with the tube sheet.
Each handle is equipped with an L-shaped supporting bracket so that when an adjacent pair of locking handles are in the horizontal position, each handle may rest within the L-shaped supporting bracket of the other to prevent the handles from pivoting back to their vertical positions to release the force securing the filter element mounting plates against the tube sheet.
When it is intended to release the filter elements from active position, one of the handles is slightly raised to clear the supporting bracket of the other handle so both handles can be lowered to vertical position to rotate the locking bars and release the force securing the filter elements in active position, whereupon they may be made to slide out of the housing.